1. Field of the Invention
The present invention relates to an electrophotographic recording type cleaning apparatus and an image forming apparatus such as a copying machine, a printer or a facsimile machine.
2. Related Background Art
A multifunction machine as an all in one output terminal including a copying machine, a printer and a facsimile and so on has been extensively available on the market. An electrophotographic system has been widely used as the above output terminal connectable to such a network. However, a duty cycle of a body is pointed out as one of serious issues. The duty cycle means the maximum limit number of the sheets within which the body may continuously work without service maintenance. A service life of a photosensitive drum may be pointed out as a critical factor of the duty cycle.
Also from an ecological point of view, it becomes an important task to obviate wasted material, i.e., to reduce the amount of consumable products, to postpone a service life of the consumable material and to enhance reliability. Also, the digitalization has been accelerated from the conventional analog apparatus. Thus, it also becomes an important task to reduce the cost of the body to the same level of the analog apparatus or less. Thus, it also becomes an important task to reduce the cost of the body to the same level of the analog apparatus or less.
Furthermore, recently, although a mono-color (black and white type) machine has been mainly conventionally used for a copying machine and a printer, a full-color output file or original has been increasingly used also in a work office. Accordingly, it becomes an important task to provide a full-color printer that has substantially the same cost of the body and of the same running cost as those of the mono-color machine. For this reason, it is desirable to provide a technology that may drastically reduce TCO (total cost of ownership).
Under such a state, recently, a color image forming apparatus which is provided with a plurality of photosensitive bodies (image bearing bodies) and a transfer belt for bearing and carrying a recording material whereby a color image may be obtained by overlapping in order toner images having different colors and formed on the photosensitive bodies, respectively, to the recording material held on this transfer belt, i.e., a four continuous drum type color image forming apparatus has been provided.
In an image forming apparatus in which a step for transferring a transferable toner image formed on an image bearing body surface to a recording material that is mainly made of paper, it is necessary to sufficiently remove residual toner residing on the image bearing body without moving to the recording material every time upon the transfer.
For this reason, various approaches have been conventionally proposed as a cleaning means for the image bearing bodies. In the above-described system, residual toner is scraped by cleaning blades made of elastic material such as urethane rubber is in practical use because of being simple in structure, compact in size, low in cost and superior in its toner-removing function. In general, urethane rubber that is very hard, abundant in elasticity and excellent in wear-resistant property, mechanical strength, oil-resistant property, and ozone-resistant property is used as the rubber material for the cleaning blades.
In the case where such a cleaning blade type cleaning apparatus is used, the toner collected by the blades is likely to reside in the vicinity of edges of the blades. If such a state is continued, a large amount of toner is likely to be present in a contact portion between the blade and the image bearing body (blade nip portion). There is a fear that a sliding friction blemish (a blemish caused by sliding) is generated on the side of the image bearing body due to inorganic particles such as external additives contained in the toner, or the like to cause an image fault.
As a method for reducing the frictional damage of the image bearing body, steps for reciprocating the cleaning blade in a longitudinal direction of the image bearing body at a predetermined width to thereby prevent the growth of the sliding friction blemish at the same position in the longitudinal direction to make the damage unremarkable have been performed.
However, even according to this method, although the sliding friction blemish of the image bearing body can be moderated, in terms of long service life and high quality, it is necessary to give a further improvement thereto.
On the other hand, as a measure for prolonging the service life of the copying machine, a chemical measure for using material that is difficult to abrade to the surface of the image bearing body to be used or for dispersing fluorine resin particles and imparting the slidability thereto and a physical measure for changing an AC charging method or a DC charging method to a corona charging method have been taken. In comparison with the AC charging method, it is confirmed that, the abrasion amount of the image bearing body is half the abrasion amount of the corona charging method or less.
By the above-described measures although the service life of the image bearing body is prolonged by the above-described method, inversely, the image bearing body is difficult to abrade. Accordingly, there is a fear that the adhesives adhered to the above-described image bearing body surface could not be scraped so that bonding or filming occurs to cause the image fault disadvantageously. Accordingly, changing the external adding method of the toner, the amount of the external additives that have the polishing effect is to be increased so that the surface of the above-described image bearing body is polished by means of the external additives interposed between the cleaning blade and the surface. Otherwise, in order to enhance the scraping ability of the cleaning blade per se, the coating layer made of material having a low frictional coefficient is provided on the surface of the blade. According to this blade, it is possible to perform the cleaning operation without fluttering (abnormal vibration) or curling of the blade, and in addition, the blade edge is very hard. Accordingly, it is possible to obtain an effect of effectively removing the adhesives adhered to the surface of the image bearing body and of suppressing the bonding or filming.
However, it becomes clear that the issue of the abrasion damage on the image bearing body surface due to the residual toner in the vicinity of the above-described blade nip particularly becomes remarkable in the case where the coating having a low wear is applied to the blade or depending upon the amount or the kind of the external additives to the toner. In general, since the coating agent is a material having a higher hardness than that of the blade base member, this is because the contact pressure of the toner that is present in the blade nip portion and the external additives to the image bearing body is increased.
In view of the above-noted defects, an object of the present invention is to provide a cleaning apparatus and/or an image forming apparatus in which a sliding friction blemish on a surface of an image bearing body can effectively be suppressed.
In order to achieve the above-mentioned object, according to the present invention, a cleaning apparatus is characterized by comprising: a cleaning member for collecting toner by contacting with a surface of an image bearing body for bearing a toner image; toner conveying means for conveying (carrying) the collected toner; and a toner breaking member disposed in the vicinity of a contact portion between the image bearing body and the cleaning member for breaking the toner in the vicinity of the contact portion, in which the toner breaking member moves in cooperation with a toner carrying operation of the toner carrying means.
According to another preferred aspect of the present invention, a cleaning apparatus is characterized by comprising: a cleaning member contacting with a surface of an image bearing member bearing a toner image for collecting toner; cleaning member moving means for holding the cleaning member and moving in reciprocation in a longitudinal direction of the image bearing body; a toner breaking member coupled with the cleaning member moving means and disposed in the vicinity of a contact portion between the image bearing body and the cleaning member for breaking the toner in the vicinity of the contact portion; and toner carrying means for carrying the collected toner, in which at least a part of the toner breaking member is arranged in a position where the part interferes with the toner carrying means.
In order to achieve the above-mentioned object, according to a preferred aspect of the present invention, an image forming apparatus is characterized by comprising: image forming means for forming a toner image on a surface of an image bearing body; transfer means for transferring the toner image on the image bearing body to a recording material; a cleaning member contacting with a surface of the image bearing body for collecting toner; toner carrying means for carrying the collected toner; and a toner breaking member disposed in the vicinity of a contact portion between the image bearing body and the cleaning member for breaking the toner in the vicinity of the contact portion, in which the toner breaking member moves in cooperation with a toner carrying operation of the toner carrying means.
According to another preferred aspect of the present invention, an image forming apparatus is characterized by comprising: image forming means for forming a toner image on a surface of an image bearing body; transfer means for transferring the toner image on the image bearing body to a recording material; a cleaning member contacting with a surface of the image bearing body for collecting toner; cleaning member moving means for holding the cleaning member and moving in reciprocation in a longitudinal direction of the image bearing body; a toner breaking member coupled with the cleaning member moving means and disposed in the vicinity of a contact portion between the image bearing body and the cleaning member for breaking the toner in the vicinity of the contact portion; and toner carrying means for carrying the collected toner, in which at least part of the toner breaking member is located in a position where the part interferes with the toner carrying means.